This multi-project program aims to discover chemokine elements which augment innate and adaptive immune responses, and determine their optimal use as potential vaccine adjuvants. Projects 1 & 2 extend our prior discoveries of two novel chemokine adjuvant candidates (PDX-S and PDX-K) which vigorously attract rodent and rhesus immature dendritic cells and monocytes in vivo, and exhibit preliminary in vivo adjuvant efficacy in adaptive immunity. Project 3 develops an array of nucleotide delivery systems for PDX-S and PDX-K which includes DNA vaccines, attenuated CMV or vaccinia viruses, and delivery in vectors additionally encoding chemokine elements which target immune hotspots (e.g. CCR7 for secondary lymphoid tissues, and MIP3a for immature dendritic cells). The current project is charged with the comprehensive evaluation of the numerous vaccine strategies, using a set of well characterized in vivo efficacy models. These include a bacterial clearance model which effectively harnesses innate immune responses, infectious disease models with attenuated CMV and vaccinia viruses, and immunoresponsiveness to protective antigens of B. anthracis and vaccinia virus, the current vaccine for variola major. In addition to the range of delivery systems, PDX-S and PDX-K will be given via different routes of administration, encompassing both systemic and mucosal approaches, at different doses, and in different formulations. Considerable effort will be focused on the issue of novel vaccine safety in immunocompomised hosts. In this context, all vaccine strategies will be evaluated in a series of immunocompromised mice, as well as in neonatal and aged mice.Experiments will initially be conducted in rodent models, with promising results reproduced in comparable non-human primate models wherever possible. Lead adjuvant candidates will be submitted to a National Biocontainment Lab for evaluation in anthrax, vaccina, and smallpox efficacy models. These studies are designed to span four years, at which stage the cumulative results will be reviewed extensively so that effective comparisons can be made, resulting in selection of the most promising candidates for continued pre-clinical development. Selection will be based on safety and efficacy data, but consideration will also be given to ease and cost of scale-up manufacturing, as well as clinical experience obtained in the field of vaccination in the ensuing period of time. An IND-path program will then be developed.